I am thinking about purchasing the Canon SD300 (4.0 MP, 3.2 Optical Zooom). I have read and heard lots of great reviews about this little camera. Does anyone have any thoughts about whether or not its a good purchase. Secondly, I heard that Canon will be releasing its new S series (currently they have the S500 and a few others as well). Is this true, and if so, when are they going to release the new S series?? Please respond ASAP